Many devices are known for dispensing molten thermoplastic materials from blocks of solid thermoplastic material manually pressed into the device.
Generally, such devices comprise a barrel member having an internal melting chamber which communicates with an outlet opening through a nozzle, and a sleeve with a through opening having one end secured to the barrel member with its through opening communicating with the end of the melting chamber opposite the nozzle. The sleeve is adapted to receive an elongate cylindrical block of solid thermoplastic material which fits closely within the through opening in the sleeve, with one end portion of the block in the melting chamber and the other end portion projecting through the sleeve. Means are provided for heating the barrel member to melt the end portion of the block therein, and the device includes a handle positioned so that an operator can grip the handle with the fingers of one hand while manually pressing the block through the sleeve and into the melting chamber to force molten thermoplastic material out of the melting chamber through the nozzle.
Two such devices for dispensing molten thermoplastic material described in my U.S. patent application No. 664,044 filed Oct. 23, 1984, of which this application is a continuation-in-part, provide, among other things, a feeding mechanism at the end of the sleeve opposite the melting chamber comprising wall means fixed to the frame and defining a passageway adapted to guide the solid thermoplastic material block in alignment with the trough opening in the sleeve, a slide having pressure surfaces adapted to receive the end portion of an operator's thumb, and being mounted on the frame for movement along a path generally aligned with the melting chamber from a retracted position spaced from the sleeve to an advanced position more closely adjacent the sleeve and back to the retracted position, the pressure surfaces being accessible by the thumb of an operator gripping the handle portion to afford manual reciprocation of the slide between the retracted and advanced positions by the operator, and the slide being adapted for engaging and advancing the block of thermoplastic material toward the melting chamber during movement of the slide from its retracted to its advanced position.